mineral

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Hardness: 5-6 (Mohs scale), Color: Sky-blue to apple-green, Luster: Waxy to subvitreous, Crystal structure: Triclinic (usually cryptocrystalline), Specific gravity: 2.6-2.9

Identified April 4, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 5-6 (Mohs scale), Color: Sky-blue to apple-green, Luster: Waxy to subvitreous, Crystal structure: Triclinic (usually cryptocrystalline), Specific gravity: 2.6-2.9

Formation & geological history

Formed by the percolation of meteoric water through aluminous rock in the presence of copper and phosphorus. Usually found in arid environments associated with volcanic rocks or sedimentary deposits.

Uses & applications

Primarily used as a gemstone in jewelry, decorative ornaments, and amulets. It is the traditional birthstone for December.

Geological facts

Turquoise is one of the oldest known gemstones, used by Ancient Egyptians, Persians, and Native Americans. It is the state gemstone of Arizona and New Mexico.

Field identification & locations

Look for its unique robin's-egg blue or green color with a waxy luster. In the field, look for thin veins or crusts in altered volcanic rocks in desert regions like the American Southwest, Iran, or China.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral